CN105436724B

CN105436724B - Method of refurbishing surface features in Bulk Metallic Glass (BMG) articles by welding

Info

Publication number: CN105436724B
Application number: CN201510612101.9A
Authority: CN
Inventors: D·J·韦伯; 高木和也
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2014-09-23
Filing date: 2015-09-23
Publication date: 2020-03-03
Anticipated expiration: 2035-09-23
Also published as: CN105436724A; US20160082537A1

Abstract

The present invention relates to a method of refurbishing surface features in bulk metallic glass articles by welding.

Description

Method of refurbishing surface features in Bulk Metallic Glass (BMG) articles by welding

In accordance with USC 35, item 119(e), the present application claims the benefit of U.S. provisional patent application serial No. 62/054,207, filed on 23/9/2014, which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to a method of refinishing surface features in a bulk metallic glass article produced by solder refinishing.

Background

Bulk Metallic Glass (BMG) and precious metal versions (pBMG) are metal alloys that do not have a crystal structure. In contrast, like glass, their structure is amorphous. BMGs have many beneficial material properties that make them useful in many engineering applications. Some properties of BMG include high strength, elasticity, corrosion resistance, and processability from the molten state.

BMGs (also referred to herein as amorphous alloys) are typically processed and shaped by cooling a molten alloy from a melting temperature above the crystalline phase (or thermodynamic melting temperature) to a "glass transition temperature" below the amorphous phase at a "sufficiently fast" cooling rate to avoid nucleation and growth of alloy crystals.

When these BMG and pBMG materials are fabricated into articles, the fabrication process may introduce surface features that may create voids in the BMG article. Typically, surface features are only visible after expensive raw materials are consumed and the production process is carried out for hours.

Disclosure of Invention

In some aspects, described herein are methods of refurbishing BMG or pBMG surfaces, including, for example, refurbishing surface features in BMG and pBMG articles that create voids and/or locally crystalline regions.

According to certain aspects, the present invention relates to methods of refurbishing surface features in BMG articles. In certain embodiments, the method includes applying a Bulk Metallic Glass (BMG) filler material comprising an alloy composition that is the same as the alloy composition of the bulk metallic glass article to the surface features such that the BMG filler material fills at least a portion of the void spaces created by the surface features. Heating the BMG filler material and a portion of the BMG article adjacent to the surface feature to a temperature above a melting temperature of the BMG filler material and the BMG article to melt the BMG filler material and the portion of the BMG article adjacent to the surface feature. The molten BMG filler material and the molten portion of the BMG article adjacent to the surface feature are cooled sufficiently quickly to a temperature below the glass transition temperature of the metallic glass article without substantially initiating crystallization.

In other aspects, the invention relates to methods of removing localized crystallization in a BMG article. In certain embodiments, the method may comprise: a locally crystallized region of a bulk metallic glass article is heated to a temperature above the melting temperature to melt the locally crystallized region. The molten locally crystallized region of the bulk metallic glass article is then cooled sufficiently rapidly to a temperature below the glass transition temperature of the metallic glass article without substantially initiating crystallization.

Drawings

While the following drawings and description show specific embodiments and examples, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

Figure 1 shows a flow diagram with the steps of a refurbishment method according to an embodiment of the present invention.

Fig. 2A provides a schematic diagram showing a BMG article having surface features according to an embodiment of the present invention.

Fig. 2B provides a schematic diagram showing a BMG article having surface features after pre-heat treatment, according to an embodiment of the present invention.

Fig. 2C provides a schematic diagram showing the application of a BMG filler material to a BMG article having surface features, according to an embodiment of the present invention.

Fig. 2D provides a schematic diagram that illustrates exposing a portion of a BMG article having surface features and a BMG filler material to a heat source, according to an embodiment of the invention.

Fig. 2E provides a schematic diagram that illustrates cooling a portion of a BMG article having surface features and a BMG filler material after exposure to a heat source, according to an embodiment of the invention.

Fig. 3A provides a schematic diagram showing a BMG article having an aperture according to an embodiment of the present invention.

Fig. 3B provides a schematic diagram showing a BMG article having pores after pre-heat treatment, according to an embodiment of the present invention.

Fig. 3C provides a schematic diagram showing the application of BMG filler material to a BMG article having pores after a preheating step, according to an embodiment of the present invention.

Fig. 3D provides a schematic diagram showing a portion of a BMG article having apertures and a BMG filler material being exposed to a heat source, according to an embodiment of the present invention.

Fig. 4 provides a schematic illustration of a time-temperature-transition (TTT) plot of an exemplary bulk-solidifying amorphous alloy.

Fig. 5A provides a schematic diagram that illustrates the application of an electron beam to a BMG article having a crystalline phase and an amorphous phase, according to an embodiment of the present invention.

Fig. 5B provides a schematic diagram that illustrates the removal of crystals in a BMG article after heating by an electron beam, according to an embodiment of the invention.

Fig. 5C provides a schematic diagram illustrating a BMG article having an amorphous layer after a polishing step, according to an embodiment of the invention.

Detailed Description

The present invention relates to methods of refurbishing surface features in BMG materials and articles. BMGs (also referred to herein synonymously as amorphous alloys) are typically processed and shaped by cooling a molten alloy from a melting temperature above the crystalline phase (or thermodynamic melting temperature) to below the "glass transition temperature" of the amorphous phase at a "sufficiently fast" cooling rate to avoid nucleation and growth of alloy crystals. BMG may refer, but is not necessarily referred to, to an amorphous alloy having or capable of forming a particular thickness.

In certain aspects, the present invention relates to methods of refurbishing surface features in BMG articles. In certain aspects, the present invention relates to methods of refurbishing surface features in BMG articles, including those that create voids. Some examples of the types of surface features that may be refurbished may be holes, pits, cracks, surface cracks, and localized crystalline regions.

BMG articles may include or consist of a metal alloy composition of a noble metal, such as a gold (Au) -based alloy, a platinum (Pt) -based alloy, or a palladium (Pd) -based alloy. Alternatively, the BMG article may comprise or consist of a nickel (Ni) -based alloy, an iron (Fe) -based alloy, a copper (Cu) -based alloy, a zinc (Zn) -based alloy, a zirconium (Zr) -based alloy, or any other metal alloy capable of forming a bulk metallic glass.

In certain embodiments, the method includes applying a Bulk Metallic Glass (BMG) filler material to a BMG article to at least partially fill the void. The BMG filler material comprises an alloy composition that is the same as an alloy composition of the bulk metallic glass article adjacent to the void, such that the BMG filler material fills at least a portion of the void space. Heating a portion of the BMG filler material and the BMG article adjacent to the void to a temperature above a melting temperature of the BMG filler material and the BMG article to melt the filler material and the portion of the BMG article adjacent to the void. The molten BMG filler material and the molten portion of the BMG article adjacent to the void are then cooled sufficiently quickly to a temperature below the glass transition temperature of the metallic glass article without substantially initiating crystallization.

In some aspects of the invention, substantially amorphous means that the volume fraction of crystals is less than 1%. In other embodiments, a volume fraction of crystals of less than 0.1% is meant, while in other embodiments, a volume fraction of crystals of 0% is meant.

Referring to fig. 1, a method 100 of refurbishing surface features in a BMG article may comprise: a step 110 of preheating a portion of the BMG article adjacent to the void; a step 120 of applying a bulk metallic glass filler material to the BMG article to partially fill the void space; a step 130 of heating the bulk metallic glass filler material and a portion of the BMG article adjacent to the void space; step 140 of cooling the molten bulk metallic glass filler material and the molten portion of the BMG article.

According to the present invention, in various embodiments, using the above-described method, surface features having a dimension of at least 0.1mm can be refurbished. Alternatively, using the method according to the invention, surface features of at least 0.5mm can be refurbished. In other embodiments, surface features having a dimension of at least 1mm can be refurbished using the methods described herein.

In some embodiments,

steps

120, 130, and 140 may be repeated sequentially in order to refurbish the surface feature. For example, if the steps of applying BMG filler material, heating and melting the BMG filler material, and cooling the filler material are performed and void spaces created by surface features remain in the BMG article, these steps may be repeated to substantially fill the void spaces. In some embodiments, substantially filling the void space refers to filling at least 99% of the void space. In other embodiments, substantially filled means that at least 99.5% of the void space has been filled. Alternatively, substantially filled means that at least 99.9% of the void space has been filled.

In other aspects, the method may include an optional step of preheating a portion of the BMG article adjacent to the surface feature to prepare the BMG article for application of the BMG filler material. For example, as shown in fig. 2A and 3A, surface features 220 or 320 (e.g., pits or holes) may be present in a BMG article and create a surface edge between the BMG article and the void space of the surface features. The surface edges of the void spaces surrounding the surface features may be sharp and/or may mask a portion of the (systematic) void spaces. The surface edges may interfere with the ability to apply BMG filler material to partially fill the void space of the surface features. Thus, in some embodiments, the step 110 of preheating and melting a portion of the BMG article adjacent to the surface feature may be performed. For the purposes of the present invention, a portion of a BMG article adjacent to a surface feature comprises: and void spaces created by surface features form regions of the BMG article that are bordered.

A portion of the BMG article adjacent to the surface feature may be selectively exposed to a heat source in order to preheat and melt a portion of the BMG article adjacent to the surface feature. The heat source may be a laser, electron beam, electrode, or other source having a controllable spot (spot) size and providing sufficient energy to heat a portion of the BMG article to a temperature sufficient to melt a surface edge between the BMG article and the surface feature. A portion of a BMG article adjacent to a surface feature may be exposed to a heat source for at least 5 milliseconds, at least 10 milliseconds, at least 20 milliseconds, or at least 50 milliseconds. Alternatively, the BMG article may be exposed to the heat source for less than 50 milliseconds, less than 25 milliseconds, less than 10 milliseconds, or less than 5 milliseconds.

The time that the BMG article is exposed to the heat source depends on the alloy composition that makes up the BMG article, the energy density of the heat source, and/or the spot size of the heat source. The exposure time may also depend on the number of pulses emitted by the heat source onto the BMG article. Alternatively, the exposure time may depend on the time of each pulse.

As shown in fig. 2B and 3B, preheating a portion of a BMG article adjacent to a surface feature may change the curvature of the edge between the BMG article and the surface features 220 and 320, thereby exposing the masked portion of the void space. The exposure of the void spaces allows

BMG fillers

230 and 330 to be more easily applied to

BMG articles

210 and 310 and improves the filling of the void spaces of surface features 220 and 320. In other embodiments, flash may be present between the BMG article and the surface feature. Portions of a BMG article adjacent to a surface feature and having flash can be preheated to a temperature sufficient to melt the BMG article, thereby removing the flash. Removal of the flash adjacent to the surface features may allow for easier application of BMG filler material to at least partially fill the surface features in the BMG article.

To refurbish surface features that include void spaces, a BMG filler material may be applied to a BMG article to fill at least a portion of the void spaces in the BMG article. In various embodiments, surface features, including defects such as holes, pits, or cracks, whether or not visible to the naked eye, may be refurbished.

BMG articles can be inherently difficult to process, mold, and solidify in the amorphous state without introducing surface features prior to the onset of crystallization. One factor that may accelerate or degrade the onset of crystallization is the grain structure of the material that may come into contact with the BMG during processing. For example, if the BMG article and BMG filler material have different compositions, phases, and cooling rates, the filler material may serve as nucleation sites for BMG crystallization. To maintain the substantially amorphous state of the BMG article, the BMG filler material may comprise the same alloy composition as the BMG article, and thus the filler material and BMG article cool at comparable rates. In addition, the BMG filler material may also be in an amorphous state. The BMG filler material should also be free of surface contaminants such as particulates, oil, or other debris. In some embodiments, the BMG filler may be pre-cleaned to remove any surface contaminants prior to applying the BMG filler material to the BMG article.

The bulk metallic glass filler material may be in the form of a sheet, a strand, a tape, a pellet, a powder, or any other form known to those skilled in the art that is suitable for application to a BMG article to at least partially fill void spaces in the BMG article created by surface features.

As shown in fig. 2C and 3C,

BMG filler material

230 and 330 is applied to surface features 220 and 320 in

BMG articles

210 and 310. Surface features 220 may be through holes extending through the thickness of the BMG article. In other cases, the surface features 320 may be pits or cracks in the BMG.

In some embodiments, the BMG filler material partially fills the void space in the BMG created by the surface features. In other embodiments, the BMG filler material may substantially fill the void space. By applying the BMG filler material to partially fill the surface features, the filler material can flow freely and fill the void spaces after the BMG filler is heated and melted, thereby refurbishing the surface features and obtaining a near-perfect BMG article free of cracks, pits, holes, and other similar surface features. In some cases, an approximately perfect BMG article may have less than 1 vol% void space. In other cases, an approximately perfect BMG article may have a void volume of less than 0.5 vol%. In further embodiments, an approximately perfect BMG article may have a void space of less than 0.1 vol%.

To allow the BMG filler material to flow into the void spaces of the surface features, the BMG filler material and a portion of the BMG article adjacent to the surface features are locally or selectively heated. The bulk metallic glass filler material and a portion of the BMG article are heated to a temperature to melt the bulk metallic glass filler material and to melt a portion of the BMG article. The BMG filler and BMG article may be selectively heated using laser welding, spot welding, arc welding, or other suitable techniques that allow for control of the area size of the BMG article exposed to the heat source.

As noted above, the time that the BMG article and BMG filler material are exposed to the heat source depends on the alloy composition making up the BMG article, the alloy composition making up the BMG filler, the energy density of the heat source, and the spot size of the heat source. The exposure time may also depend on the number of pulses of the heat source emitted onto the BMG article. Alternatively, the exposure time may also depend on the heating rate (in K/sec), the energy per pulse and/or the pulse time.

As shown in fig. 2D and 3D, the BMG filler material and a portion of the BMG article adjacent to the surface feature are exposed to the heat source while the remainder of the BMG article is not exposed to the heat source. The heat source may be a laser, an electrode, or other source having a controllable spot size and may provide sufficient energy to heat the BMG filler and a portion of the BMG article to a temperature sufficient to melt the BMG filler and a portion of the BMG article. The use of a laser or an electrode as a heat source allows for localized heating and melting of the filler material and a portion of the BMG article. Thus, the entire BMG article does not melt and maintain the overall shape and integrity of the BMG article during the refurbishment process.

Useful laser types include CO₂(carbon dioxide), CO (carbon monoxide), Nd: YAG laser or any other suitable laser.

In some embodiments, the BMG filler and a portion of the BMG article may be exposed to the heat source for at least 5 milliseconds, at least 10 milliseconds, at least 20 milliseconds, or at least 50 milliseconds. Alternatively, the BMG article may be exposed to the heat source for less than 50 milliseconds, less than 25 milliseconds, less than 10 milliseconds, or less than 5 milliseconds.

In other embodiments, the BMG filler and a portion of the BMG article may be heated by repeated short exposures to a heat source. For example, the laser or electron beam may be repeatedly pulsed to provide less than 10 milliseconds per pulse, less than 5 milliseconds per pulse, and/or less than 1 millisecond per pulse of energy to the BMG filler and BMG article.

Without wishing to be bound by any theory or mechanism of action, BMG alloys may be sensitive to oxygen content. For example, oxides in the alloy may promote nucleation of crystals, thereby reducing the formation of an amorphous microstructure. Some amorphous alloy compositions form a permanent oxide layer, which can interfere with the melting of the particles. In addition, surface oxides may also be incorporated into the bulk alloy and may reduce the glass forming ability of the alloy. Thus, in certain embodiments, it may be desirable to protect the BMG article, remove oxygen from the interface between the filler material and the BMG article, and from the final part, under an inert atmosphere, a reducing atmosphere, or in a vacuum while heating the filler material. For example, the heating may be performed in a chamber under vacuum (e.g., 1-10 millitorr), a reducing atmosphere (e.g., hydrogen or a mixture of hydrogen and nitrogen), or an inert atmosphere (e.g., argon, nitrogen). The chamber may be pumped by a vacuum pump. Alternatively, the inert gas may be flowed locally to a portion of the BMG filler material and BMG article being heated by the heat source.

After heating, a cooling step 140 is performed. As described herein, cooling may include cooling the molten BMG filler material and the molten portion of the BMG article at ambient temperature and atmospheric air. In step 140, the molten BMG filler material and the molten portion of the BMG article are cooled sufficiently quickly to a temperature below the glass transition temperature of the BMG article and BMG filler without substantially initiating crystallization. The lowest rate at which the BMG can be cooled to avoid crystallization and thereby obtain and maintain an amorphous structure during cooling is referred to as the critical cooling rate of the bulk alloy.

In other embodiments, to cool sufficiently quickly to a temperature below the glass transition temperature without substantially initiating crystallization, the BMG article may be pre-chilled or cooled prior to application of the filler material. The BMG article may be pre-chilled by blowing with cold air or any other suitable cooling method. It may be desirable to pre-chill the BMG article prior to applying the BMG filler material to create a negative heat sink to extract heat from the molten BMG filler and the molten portion of the BMG article.

Fig. 4 (obtained from U.S. patent 7,575,040, incorporated herein by reference) shows a time-temperature-transformation (TTT) cooling curve or TTT diagram for an exemplary bulk-solidifying amorphous alloy. Bulk solidifying amorphous metals do not undergo a liquid/consolidated crystal transition upon cooling as do conventional metals. In contrast, the highly fluid, amorphous form of the metal found at high temperatures (near the "melting temperature" Tm) becomes more viscous with decreasing temperature (near the glass transition temperature Tg), eventually assuming the external physical properties of a conventional solid.

Although bulk solidifying amorphous metals do not exhibit a liquid/consolidated crystal transition, the melting temperature, Tm, can be defined as the thermodynamic liquidus temperature of the corresponding crystalline phase. Under this mechanism, the viscosity of bulk-solidifying amorphous alloys at the melting temperature may be in the range of about 0.1 poise to about 10000 poise, and even sometimes below 0.01 poise. Lower viscosity at "melt temperature" will provide faster and complete filling of void space in BMG articles caused by surface features. Furthermore, the cooling rate of the molten BMG filler and a portion of the BMG article must be such that the time-temperature curve during cooling does not traverse the nose-shaped region in the TTT diagram of fig. 4 that defines the crystalline region. In FIG. 4, T_NoseAt the critical crystallization temperature Tx, where crystallization is fastest and occurs in the shortest time scale.

The supercooled liquid region (temperature region between Tg and Tx) is an expression of the stability of the bulk solidifying alloy with respect to the crystallization. In this temperature region, the bulk-solidifying alloy may exist as a highly viscous liquid. The viscosity of the bulk solidifying alloy in the supercooled liquid region may be 10 at the glass transition temperature¹²Pa.s to 10 at the crystallization temperature (high temperature limit of supercooled liquid region)⁵Pa · s. Liquids having this viscosity can experience significant plastic strain under the applied pressure. The embodiments herein utilize large plastic formability in the supercooled liquid region as a forming and separating method.

From a technical point of view, the nose curve shown in the TTT diagram describes Tx as a function of temperature and time. Thus, regardless of the trajectory that a BMG filler and a portion of a BMG article take on heating and cooling, it reaches Tx when it contacts the TTT curve. In fig. 4, Tx is shown as a dashed line, where Tx can vary from near Tm to near Tg.

The schematic TTT plot of fig. 4 shows the die casting process from Tm or above to below Tg, while the time-temperature trace (shown as (1) as an exemplary trace) is not in contact with the TTT curve. During molding, the forming and rapid cooling are performed substantially simultaneously to avoid the traces contacting the TTT curve. FromThe time-temperature traces (shown as (2), (3), and (4) as exemplary traces) of the superplastic forming (SPF) processing method at or below Tg to below Tm do not contact the TTT curve. In SPF, amorphous BMG is reheated into the supercooled liquid region, where the available processing window can be much larger than die casting, resulting in a more controllable process. The SPF process does not require rapid cooling to avoid crystallization during cooling. Further, as shown by exemplary traces (2), (3), and (4), SPF may be implemented during SPF at a maximum temperature that is higher than T_NoseOr below T_NoseUp to about Tm. If an amorphous alloy is heated but does not intersect the TTT curve, the alloy is heated "between Tg and Tm" but does not reach Tx.

A typical Differential Scanning Calorimeter (DSC) heating curve for a bulk-solidifying amorphous alloy obtained at a heating rate of 20 ℃/minute describes, to a large extent, a particular trace through the TTT data, where it is possible to see the Tg at a particular temperature, the Tx when the DSC heating curve crosses the TTT crystallization onset line, and the final melting peak (when this same trace crosses the melting temperature range). If a bulk-solidifying amorphous alloy is heated at a rapid heating rate as shown by the ascending portions of traces (2), (3), and (4) in fig. 4, the TTT curve can be completely avoided and the DSC data will show a glass transition upon heating, but no Tx. Another way contemplated is that traces (2), (3) and (4) may fall at any temperature between the nose of the TTT curve (even higher) and the Tg line, as long as they do not contact the crystallization curve. This means exactly that the horizontal plateau of the trajectory can become significantly shorter as the process temperature increases.

In other embodiments, localized crystallization may be removed from the BMG article. The method includes heating a locally crystalline portion of a BMG article to remelt the locally crystalline portion of the BMG article and cooling sufficiently quickly to a temperature below the glass transition temperature of the BMG article without substantially initiating crystallization. The locally crystalline portion of the BMG article may be heated using any of the heat sources described above. All variations described herein for refurbishing or refurbishing BMG articles having surface characteristics can be used herein.

Without wishing to be limited, for example, localized crystalline regions may be found on the exterior surface of a BMG article. As shown in fig. 5A, crystalline regions 510a may be present in a BMG article along with an amorphous phase. In some embodiments, to remove local crystals on the exterior surface, an electron beam may be applied to the local crystals and a portion of the surface of the BMG article. The electron beam provides a source of energy that can melt at least a portion of the outer surface of the BMG article.

In some embodiments, as shown in fig. 5B (which shows removal of the crystals after application of the electron beam), the electron beam may enter the BMG article to a depth of up to 5 μm, thereby heating and remelting the localized crystals. BMG articles can be treated with e-beam for short treatment times (e.g., at least several milliseconds). In some embodiments, the e-beam may enter the BMG article to a depth of at least 1 μm, and in other embodiments to a depth of at least 4 μm. In other embodiments, the e-beam may enter the BMG article to a depth of 5 μm or less, and in other embodiments, the depth of entry may be 4 μm or less. In further embodiments, a laser or an electrode may be used as a heat source. The laser or electrode may enter the BMG article to a depth of greater than 5 μm, and in some embodiments greater than 10 μm.

After heating and melting the partially crystallized portion of the BMG article, it may be cooled sufficiently quickly to a temperature below the glass transition temperature of the BMG article without substantially initiating crystallization, thereby forming a substantially amorphous exterior surface 510B (as shown in fig. 5B). In some embodiments, substantially amorphous means that the volume fraction of crystals is less than 0.1%. In other embodiments, it refers to a volume fraction of crystals of less than 0.05%, while in other embodiments, it refers to a volume fraction of crystals of 0%. In some embodiments, as shown in fig. 5C, the surface of the BMG article may be further polished.

In other embodiments, the methods according to the present invention may be used to enhance BMG articles. In some embodiments, to reinforce a BMG article, the method includes applying a BMG filler material for the BMG article to at least a portion of the BMG article. Heating the BMG filler material and a portion of the BMG article to which the BMG filler is applied to a temperature above a melting temperature of the BMG filler material and the BMG article to melt the filler material and the portion of the BMG article to which the BMG filler is applied. The molten BMG filler material and the molten portion of the BMG article with the BMG filler applied thereto are then cooled sufficiently quickly to a temperature below the glass transition temperature of the metallic glass article without substantially initiating crystallization. All of the variations described herein for refurbishing BMG articles having surface features can be used herein.

In other embodiments, the methods according to the present invention may be used for additive manufacturing of BMG articles (additive manufacturing). For example, without wishing to limit the invention to a particular BMG article, the methods described herein may be used to join at least two BMG articles, such as a boss (boss) and a housing. In some embodiments, the BMG filler material may be applied to a surface connecting at least two BMG articles. Heating the BMG filler material and the at least two BMGs to a temperature above the melting temperature of the BMG filler material and the at least two BMG articles to melt the filler material and to melt at least a portion of the at least two BMG articles to which the BMG filler is applied. The molten BMG filler material and the molten portions of the at least two BMG articles to which the BMG filler is applied are then cooled sufficiently quickly to a temperature below the glass transition temperature of the metallic glass article without substantially initiating crystallization. Here, all of the protocols described herein for refurbishing BMG articles having surface features may be used.

The methods described herein may be valuable in the manufacture of electronic devices using BMG-containing parts. An electronic device herein may refer to any electronic device known in the art. For example, it may be a telephone, such as a mobile telephone, and a land-line telephone, or any communication device, such as a smart phone, including for example

And an e-mail transmitting/receiving device. It may be a display such as a digital display, a TV monitor, an electronic book reader, a portable web browser (e.g. a desktop computer or a mobile phone)

) And calculatingA portion of a machine monitor. It may also be an entertainment device including a portable DVD player, a conventional DVD player, a Blu-ray disc player, a video game controller, a music player such as a portable music player (e.g., a DVD player, a DVD

) And the like. It may also be part of a device that provides control, e.g. controlling a stream of images, video, audio (e.g. Apple)

) Or it may be a remote control of the electronic device. It may be part of a computer or its accessories such as a hard drive tower housing (towerhousing) or jacket, a notebook housing, a notebook keyboard, a notebook touchpad, a desktop computer keyboard, a mouse, and a speaker. The article of manufacture may also be applied to a device such as a watch or clock.

While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed herein, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A method of refurbishing a BMG article having surface characteristics, the method comprising:

preheating a portion of a BMG article adjacent to a surface feature to a temperature sufficient to melt the portion of the BMG article;

applying a BMG filler material to the surface feature, wherein the BMG filler material comprises an alloy composition that is the same as an alloy composition of the BMG article;

heating the BMG filler material and a portion of the BMG article adjacent to the surface feature to a temperature above the melting temperature of the BMG filler material, thereby melting the filler material and a portion of the BMG article adjacent to the surface feature; and

the molten BMG filler material and the molten portion of the BMG article adjacent to the surface feature are cooled sufficiently quickly to a temperature below the glass transition temperature of the metallic glass article without substantially initiating crystallization.

2. The method of claim 1, wherein the BMG filler material fills the entire void space created by the surface features.

3. The method of claim 1, wherein the surface features are at least 0.1 mm.

4. The method of claim 1, wherein the surface features are at least 0.5 mm.

5. The method of claim 1, wherein the surface feature is at least 1 mm.

6. The method according to claim 1, wherein the heating step is performed using a laser, an electron beam, or an electrode.

7. The method of claim 1, wherein the BMG filler material is in an amorphous state.

8. The method of claim 1, wherein the BMG filler material is a sheet, strand, tape, pellet, or powder.

9. A method of refurbishing a BMG article having surface features including selected localized crystalline regions, comprising:

heating the selected locally crystalline region of the BMG article to a temperature above the melting temperature of the BMG article to melt the locally crystalline region to remove the surface feature; and

the locally crystallized molten region of the BMG article is cooled sufficiently quickly to a temperature below the glass transition temperature of the BMG article without substantially initiating crystallization.

10. A method according to claim 9, wherein the locally crystalline region is at least 0.1 mm.

11. A method according to claim 9, wherein the locally crystalline region is at least 0.5 mm.

12. A method according to claim 9, wherein the locally crystalline region is at least 1 mm.

13. The method according to claim 9, wherein the heating step is performed using a laser, an electron beam, or an electrode.

14. A method of refurbishing a portion of a surface feature of a BMG article, the method comprising:

preheating a portion of a BMG article adjacent to a surface feature;

at least partially filling the surface features with a BMG filler material;

melting a BMG filler material and a portion of a BMG article adjacent to a surface feature; and

the BMG filler material and a portion of the BMG article adjacent to the surface feature are cooled sufficiently quickly to a temperature below the glass transition temperature of the BMG without substantially initiating crystallization.

15. The method of claim 14, wherein the BMG filler material fills the entire void space created by the surface features.

16. The method of claim 14, wherein the surface features are at least 0.1 mm.

17. The method of claim 14, wherein the surface features are at least 0.5 mm.

18. The method of claim 14, wherein the surface feature is at least 1 mm.

19. The method of claim 14, wherein the heating step is performed using a laser, an electron beam, or an electrode.

20. The method according to claim 14, wherein the BMG filler material is in an amorphous state.